Profiling of tyrosine phosphorylation pathways in human cells using mass spectrometry

The reversible phosphorylation of tyrosine residues is an important mechanism for modulating biological processes such as cellular signaling, differentiation, and growth, and if deregulated, can result in various types of cancer. Therefore, an understanding of these dynamic cellular processes at the molecular level requires the ability to assess changes in the sites of tyrosine phosphorylation across numerous proteins simultaneously as well as over time. Here we describe a sensitive approach based on multidimensional liquid chromatography/mass spectrometry that enables the rapid identification of numerous sites of tyrosine phosphorylation on a number of different proteins from human whole cell lysates. We used this methodology to follow changes in tyrosine phosphorylation patterns that occur over time during either the activation of human T cells or the inhibition of the oncogenic BCR-ABL fusion product in chronic myelogenous leukemia cells in response to treatment with STI571 (Gleevec). Together, these experiments rapidly identified 64 unique sites of tyrosine phosphorylation on 32 different proteins. Half of these sites have been documented in the literature, validating the merits of our approach, whereas motif analysis suggests that a number of the undocumented sites are also potentially involved in biological pathways. This methodology should enable the rapid generation of new insights into signaling pathways as they occur in states of health and disease.     

Lived experience in teaching mental health nursing: Issues of fear and power

Australian mental health policy clearly articulates recovery focus as the underpinning of mental health services. Barriers to achieving a recovery focus are identified in the literature, with negative attitudes of health professionals receiving particular attention. The involvement of people with lived experience of significant mental health challenges and mental health service use is essential to enhancing more positive attitudes. Lived‐experience involvement in the education of nurses is evident; however, it is generally limited and implemented on an ad hoc basis. Overall, there is a paucity of literature on this topic. A qualitative exploratory study was undertaken to elicit the views and perceptions of nurse academics and lived‐experience educators about the inclusion of lived experience in mental health nursing education. One major theme to emerge from the research was issues of fear and power, which included three subthemes: facing fear, demystifying mental illness, and issues of power. Lived‐experience involvement has an important role to play in the education of nurses in addressing fear and demystifying the experience of mental illness. The power that lived‐experience educators exercised in their roles varied considerably, and for many, was limited. Therefore, the effectiveness of lived‐experience involvement requires a more equitable distribution of power.     

Atomistic investigation of an Iowa Amyloid-β trimer in aqueous solution

The self-assembly of Amyloid beta (Aβ) peptides are widely accepted to associate with Alzheimer''s disease (AD) via several proposed mechanisms. Because Aβ oligomers exist in a complicated environment consisting of various forms of Aβ, including oligomers, protofibrils, and fibrils, their structure has not been well understood. The negatively charged residue D23 is one of the critical residues of the Aβ peptide as it is located in the central hydrophobic domain of the Aβ N-terminal and forms a salt-bridge D23-K28, which helps stabilize the loop domain. In the familial Iowa (D23N) mutant, the total net charge of Aβ oligomers decreases, resulting in the decrease of electrostatic repulsion between D23N Aβ monomers and thus the increase in their self-aggregation rate. In this work, the impact of the D23N mutation on 3Aβ_11–40 trimer was characterized utilizing temperature replica exchange molecular dynamics (REMD) simulations. Our simulation reveals that D23N mutation significantly enhances the affinity between the constituting chains in the trimer, increases the β-content (especially in the sequence 21–23), and shifts the β-strand hydrophobic core from crossing arrangement to parallel arrangement, which is consistent with the increase in self-aggregation rate. Molecular docking indicates that the Aβ fibril-binding ligands bind to the D23N and WT forms at different poses. These compounds prefer to bind to the N-terminal β-strand of the D23N mutant trimer, while they mostly bind to the N-terminal loop region of the WT. It is important to take into account the difference in the binding of ligands to mutant and wild type Aβ peptides in designing efficient inhibitors for various types of AD.

Amyloid beta peptide oligomers are believed to play key roles in Alzheimer''s disease pathogenesis. D23N mutation significantly changes their structure and how they bind potential inhibitors.     

The value of repeated determinations of brain natriuretic peptide for the diagnosis of unstable angina

The diagnosis of unstable angina (troponine undetectable) is often difficult in the absence of electrocardiographic changes after suggestive chest pains. The object of this study was to analyse the kinetics of Brain Natiuretic Peptide (BNP) during acute coronary syndromes (ACS) without ST elevation. Plasma BNP was measured every 6 hours for 48 hours in 65 patients admitted for suspicion of ACS without ST elevation and without clinical, radiological or echocardiographic signs of left ventricular dysfunction. The results of BNP measurements were masked until the final diagnosis was established on the usual investigations (ECG changes, troponine I values, myocardial scintigraphy, coronary angiography). These investigations identified 3 groups of patients: non-Q wave infarction (group A: 19 patients), unstable angina (group B: 21 patients) and non-coronary chest pain (group C: 25 patients). The peak BNP was significantly higher in groups A (210 +/- 172 pg/ml) and B (152 +/- 159 pg/ml) than in group C (16 +/- 14 pg/ml). However, the BNP was normal or only slightly increased (< 50 pg/ml) in 25% of cases of ACS. Analysis of the kinetics of BNP was much more discriminating: early increase after the pain, peak between the 14th and 24th hours (19th hour on average), followed by a progressive decrease. The kinetics were identical in Groups A and B, contrasting with the flat profile of the curve in group C. A change of > 20 pg/ml in BNP was a better criterion of ACS with a diagnostic accuracy > 90% than increased troponine (group A) or undetectable troponine (group B). The authors conclude that BNP kinetics is a new and reliable diagnostic marker of unstable angina when the usual criteria of ACS are not present (notably a normal ECG and undetectable troponine).     

Mental Health Nurse Incentive Program: Facilitating physical health care for people with mental illness?

People with serious mental illness have increased rates of physical ill‐health and reduced contact with primary care services. In Australia, the Mental Health Nurse Incentive Program (MHNIP) was developed to facilitate access to mental health services. However, as a primary care service, the contribution to physical health care is worthy of consideration. Thirty‐eight nurses who were part of the MHNIP participated in a national survey of nurses working in mental health about physical health care. The survey invited nurses to report their views on the physical health of consumers and the regularity of physical health care they provide. Physical health‐care provision in collaboration with general practitioners (GPs) and other health‐care professionals was reported as common. The findings suggest that the MHNIP provides integrated care, where nurses and GPs work in collaboration, allowing enough time to discuss physical health or share physical health activities. Consumers of this service appeared to have good access to physical and mental health services, and nurses had access to primary care professionals to discuss consumers’ physical health and develop their clinical skills in the physical domain. The MHNIP has an important role in addressing physical health concerns, in addition to the mental health issues of people accessing this service.     

The brain‐derived neutrophic factor val66met polymorphism and sudden unexpected infant death

Aim: Findings of hypoxia prior to death and involvement of a dysregulation of the serotonergic network in sudden infant death syndrome (SIDS) may indicate that brain‐derived neutrophic factor (BDNF) also is of importance with regard to sudden unexpected infant death. Based on this, the purpose of this study was to investigate the BDNF val66met polymorphism in SIDS cases, cases of infectious death and controls. Methods: The polymorphism was investigated in 163 SIDS cases, 34 cases of infectious death and 121 controls, using real‐time PCR and fluorescence melting curve analysis. Results: There were no differences in val66met genotype distribution between neither the SIDS cases nor the cases of infectious death and controls (p = 0.95 and p = 0.52, respectively). Conclusion: The study indicates that the val66met polymorphism is not important for sudden unexpected infant death. However, several other SNPs in the BDNF gene, as well as in other genes involved in this pathway, including G‐protein, have to be investigated to fully exclude any involvement of BDNF in SIDS.     

The humoral antibody response to Shigella dysenteriae type 1 infection, as determined by ELISA

An enzyme-linked immunosorbent assay (ELISA) for determining the class-specific humoral antibody response to the lipopolysaccharide antigen from Shigella dysenteriae serotype 1 bacteria has been tested. Two or more serum samples from each of 60 persons infected with this organism during a dysentery outbreak in a boarding school for young men near Haiphong, Viet Nam, and single serum samples from 39 healthy Vietnamese and from 20 healthy Swedes were included in the study. Comparison of the titres in the sera from the patients and the Vietnamese controls showed that the patients had significantly elevated IgA titres in sera collected 10, 30 and 45 days after onset of infection, and significantly elevated IgG titres in sera collected 30, 45 and 180 days after the onset. The titres in the patients'' sera, compared with those in the Swedish controls, were significantly elevated for IgA and IgM as well as IgG in the samples collected after 10, 30, 45 and 180 days. The use of rabbit antisera, specific for enteropathogenic bacteria, and absorption experiments with human sera indicated that the S. dysenteriae type 1 lipopolysaccharide antigen is specific with respect to the O-antigenic polysaccharide chain.